Perceptual variation may represent an important aspect of genetic differences in human ingestive behavior (eg why we choose to eat and drink some foods and beverages but not others). This proposal represents a collaborative effort between investigators in chemosensory psychophysics, and molecular and quantitative behavioral genetics to examine how genetic variation in taste and pain receptors in the mouth may alter response to oral irritants that are commonly found in the food supply. Here, we propose a laboratory study to quantify the impact of variation in specific genes on the sensations that arise from capsaicin (the compound responsible for the heat of 'hot'peppers), piperine (the compound responsible for the burn of black pepper) and ethanol. Previously, we found capsaicin and piperine are bitter to some individuals but not others. Now, we ask if genetic variation in bitter taste genes can explain why. Analyses under Specific Aims 1-3 will determine if common polymorphisms (alternative forms of a gene) for the TRPV1 receptor predict differential response to the burning sensations from these irritants. Secondary aims test if certain variants of bitter taste genes can explain differences in the bitterness of these irritants. Important covariates include frequency of spicy food intake, personality factors (novelty seeking, and sensation seeking) and underlying differences in the intensity of oral sensations (supertasting). At the conclusion of this project, we will have produced a body of valuable data addressing the contribution of genetic polymorphisms on the burn and bitterness of oral irritants. Better understanding of the biology behind irritancy and bitterness will inform attempts to develop methods to block or mask these sensations and potentially remove palatability as a barrier to medication compliance. Proposed work may also provide new insight with respect to food choice behavior or causes of oral pathologies that involve burning sensations.

Public Health Relevance

Taste is the main gatekeeper of ingestion: humans generally swallow what they like and reject what they don't, and what is liked may differ with genetics. This research examines whether the burning and bitterness from natural chemicals found in common spices are related to genetic differences in perception. Better understanding of the basic biology behind bitterness and irritancy will help us understand the dietary choices individuals make, and may help us tailor diets that improve health and wellness while remaining enjoyable to eat.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Small Research Grants (R03)
Project #
Application #
Study Section
Special Emphasis Panel (ZDC1-SRB-Q (65))
Program Officer
Sullivan, Susan L
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Pennsylvania State University
Schools of Earth Sciences/Natur
University Park
United States
Zip Code
Coupland, John N; Hayes, John E (2014) Physical approaches to masking bitter taste: lessons from food and pharmaceuticals. Pharm Res 31:2921-39
Allen, Alissa L; McGeary, John E; Hayes, John E (2014) Polymorphisms in TRPV1 and TAS2Rs associate with sensations from sampled ethanol. Alcohol Clin Exp Res 38:2550-60
Feeney, Emma L; Hayes, John E (2014) Exploring associations between taste perception, oral anatomy and polymorphisms in the carbonic anhydrase (gustin) gene CA6. Physiol Behav 128:148-54
Feeney, Emma L; Hayes, John E (2014) Regional differences in suprathreshold intensity for bitter and umami stimuli. Chemosens Percept 7:147-157
Harwood, Meriel L; Loquasto, Joseph R; Roberts, Robert F et al. (2013) Explaining tolerance for bitterness in chocolate ice cream using solid chocolate preferences. J Dairy Sci 96:4938-44
Byrnes, Nadia K; Hayes, John E (2013) Personality factors predict spicy food liking and intake. Food Qual Prefer 28:213-221
Rawal, Shristi; Hayes, John E; Wallace, Margaret R et al. (2013) Do polymorphisms in the TAS1R1 gene contribute to broader differences in human taste intensity? Chem Senses 38:719-28
Harwood, Meriel L; Ziegler, Gregory R; Hayes, John E (2013) Tolerance for high flavanol cocoa powder in semisweet chocolate. Nutrients 5:2258-67
Sharafi, Mastaneh; Hayes, John E; Duffy, Valerie B (2013) Masking vegetable bitterness to improve palatability depends on vegetable type and taste phenotype. Chemosens Percept 6:8-19
Allen, Alissa L; McGeary, John E; Knopik, Valerie S et al. (2013) Bitterness of the non-nutritive sweetener acesulfame potassium varies with polymorphisms in TAS2R9 and TAS2R31. Chem Senses 38:379-89

Showing the most recent 10 out of 14 publications